Portable tool double-pole trigger switches for speed control have been known heretofore. H. W. Brown U.S. Pat. No. 3,775,576, dated Nov. 27, 1973, shows such a double-pole speed control trigger switch. However, in that and other prior art devices of that type, a large heat sink has been required, to which the semiconductor means has been mounted to dissipate the heat. This heat sink took up a lot of room inside the base, thus requiring the use of a special small semi-conductor device that could be soldered directly to the heat sink. While these prior devices have been useful for their intended purposes, this invention relates to improvements thereover.